Centerless grinder



Oct. 22, 1929. H. w. HOLMES 1,733,090

CENTERLESS GRINDER Original Filed Nov. 5. 1925 6 Sheets-Sheet 1 0ct. 22,11929. H, w, HOLMES 1,733,090

GENTERLESS GRINDER Original Filed Nov. 5, 1923 6 Sheets-Sheet 2 INVEN TOR.

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Oct. 22, 1929. H. w. HOLMES 1,733,090

cENTERLEss GRINDER Original Filed Nov. 5, 1925 6 Sheets-Sheet 3 INVENTOR.

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'CENTERLES S GRINDER Original Filed Nov. 5, 1923 6 Sheets-Sheet 4 mms/T015.

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H. W. HOLMES cENTERLEss GRINDER oct. 22, 1929.

vOriginal Filed Nov. 5. 1923 6 Sheets-#Sheet 5 Oct. 22 1929. H. w. HOLMES 1,733,090

CENTERLESS GRINDER Original Filed Nov. 5, 1923 6 Sheets-Sheet 6 IN YENTOR ATTO may Patented oer. 22, 1929 UNITED STATES gPa'rErrr OFFICE HAROLD W. HOLMES, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CINCINNATI GRINDERS INCORPORATED, OF CINCINNATI, OHIO, A CORPORATION OF OHIO -Application file d November 5, 1923, Serial No. 672,844. Renewed March 1, 1929.

I a'high degree of accuracy and precision ofv grinding. Another obJect is toprovide an apparatus of the above-mentioned character adapted for convenient and speedy manual control and adjustment and adapted for rapid and convenient control to meet the varying conditions of practical use. Forexample, and as conducive to a clearer understanding of certain features and objects of this invention, it may here be noted that the l grinding apparatus includes a grinding wheel and a coacting wheel for causing the round work to move along past the face of the grinding wheel and toturn the w'ork as the lattermoves along ;this coacting wheel, which 26 I prefer to term the work-rotating wheel, ro- -tates at a verylow rate of speed but, like the grinding wheel, it has to be trued from time to time. One of the objects of this invenf tion is to provide a compact, dependable and 30 easily controlled mechanism for quickly changing the speed of this coacting wheel from a worlrturnin'g speed to the much higher speed required to true the wheel. Another obj ect is to provide a simple and efficient mechanism for truing the grinding wheel and the workrotating wheel. v

Another object of this invention is to provide a grinding apparatus in which a dependable driving of the grinding wheel'at its appropriate cutting speed may be achievedbut in a manners free from detrimentally affecting the accuracy or precision of action of the grinding wheel or of its coacting mechanisms. Other objects will be in part obvious or in part pointed out hereinafter. v'

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be 5 exemplified in the structure to be hereinafter described and the scope ofthe application of which will be indicated in the following claims. I

In the accompanying drawings in which is hown a preferred embodiment of this invenion,

Figure 5 is a vertical-section taken along the axis of the upper orgrinding wheelof4 the apparatus;

f Figure 6 is a horizontal sectional view taken along the line 6-6 of Figure 5;

Figure 7 is a side elevation (as seen from the left in Figure 4) of a portion of the driving mechanism' for the lower or workrotating wheel, certain .parts being broken away in order to show the construction more clearly, and i Figure 8 is a horizontal sectional view taken along the line 8-8 of Figure 7.

Similar reference characters refer to like Figure 1 is a left sideelevation of the.

parts throughout the several views in the drawings. A

Referring now to the drawings and more particularlyv to, Figure 1, there is shown a main frame 1 supporting at its upper righthand portion a grinding wheel 18 by a bearing construction preferably such as that illustrated in Figure 5. Referring to the latter figure, the grinding wheel 18 is preferably mounted upon a collar 33 which is carried by and clamped upon the tapered end portion of the grinding wheel spindle 17, a ring 34 detachably connected to the collar 33 b the screws 35 detachably holding the grin ing wheel 18 on the collar 33 and hence upon the spindle 17. The spindle 17 isrotatably supported in bearings 19 and 20 which, with their associated structural features, are preferably of the type and construction sub'- stantially as shown in Patent No. 1,408,837

of March 7, 1922. More specifically, it may be noted here that the bearings 19 and 2O are supported inv bushings 25 and 26 respectively, these bushings being tapered on their inside While the bearings 19- and 2O are tapered on their .outside to fit into these bushings, as' will be'clear from Figure 5. The-bearings 19 and 20 areadjustable longitudinally with respect to the bushings 25 and 26y respectively by the nuts or threaded collars 21 and 22 associated with the bearing 19 and the bushing 25 and the nuts or collars 23 and 24 associated with the bearing 2O and .'over the grinding wheel driving pulley 5.

In order to prevent the pull of the belt 4 from causing uneven wear at the bearings 19 and 20 of the grinding wheel spindle 17 and from otherwise detrimentally affecting the precision of action of the grinding wheel and its associated parts, the pulley 5 (see Figure 5) is mounted rotatably upon a short shaft 6 which is in substantial alinement with the spindle 17 and is rigidly supported from the main frame 1 by the arm or bracket 13 (see also Figure 1). The pulley 5 is preferably mounted upon this stud shaft 6 by means of ball bearings 14 and 15 and it will be noted -that by the construction thus provided the tension or pull of the belt 4, which may be tightened to any desired extent by appropria-tely' adjusting t-he idler pulleys 7 and 8 which are carried in the piv'otally mounted frame 9 (see Figure 1), reacts upon the shaft 6 and through the bracket 13 upon the main frame 1. Between the pulley 5 and the spindle 17 there is provided a connection which transmitsfrom the former to the latter simply the driving torque of the pulley 5. This connection preferably consists of a iiexible link 30 preferably of leather or suitable fabric, the link 30 being secured, by means of-bolts 31, tothe pulley 5 and to an arm 29, the latter being ixedly secured to the lefthand end of the .grinding wheel spindle 17 as will be clear from Figure 5. Thus, the pullor tension of the belt is prevented from being exerted upon the spindle 17 and lthrough the latter upon the bearings. 19 and 20 yand thusthe life of the bearings is greatly prolonged, 'greater` accuracy and precision may be maintained,and driving losses due to friction and consequent heating greatly minimized. c

The lower right-hand portion of the main frame 1, as seen in Figure 1, is provided with a standard 40 positioned substantially underneath the overhanging grinding wheel 18; a portion 41 of the standard 40 (see Figure 4) is of substantially cylindrical form or shape and receives therein a cylindrical ram 39. This ram 39 may be raised or lowered within the standard 41 by means of the hand wheel 45 which actuates a suitable-mechanism (not illustrated) for effecting this raising and lowering of the ram 39 and its associated partis. The ram 39 is provided with a longitudinally extending keyway (see Figure 4) with which engagesl portion Vof the standard 41, as will be clear from Figure 4. The cylindrical standard 41 is split see Figure 4) and by means of the handle 43 the ram 39 may be clamped securely within the standard 41.

The upper portion `of the ram 39 is provided With a head 42 which in turnhas secured thereto or mounted thereon a frame 46 (see Figures 4, 3 and 2) and the frame 46 is provided with two upwardly directed spaced arms in which are carried the bearings47 and 48 for an arbor or spindle 49 upon which is carried the kwork-supporting and feeding wheel 50, the relation of the various parts being such that the wheel 50 is thus rotatably supported substantially underneath grinding wheel 18 (see Figure 1). The width of the face of the lower wheel 50 is materially greater than the width of the grinding wheel 18as will be clear from Figure 2 wherein the grinding Wheel is indicated in dotted lines at 18; by this arrangement many great advantages in the `action of the apparatus are achieved as will be made more clear hereinafter. Preferably also the center of the lower wheel is substantially directly under the axis of the upper or grinding wheel 18 and by means of the construction hereinabove described the lower wheel 50 may be raised or lowered by manipulation of theihand Wheel 45 (see Figure 4) and may be tilted about the axis of tlie'ram 39 to an extent indicated by the indicia on the collar 44.

the.

The spindle 49 of the work-feeding and rotating wheel 50 is provided at its left-hand a worm wheel 62 through either of Vwhich the vs, indle 49 may be driven. The frame 46 (see,

i v igure 4) is `provided'at its left-handgend with a housing generally indicated at 52, this housing being of a general cylindrical shape and extending substantially vertically (see also Figure 7 )"I Within this cylindrical housing 52 there is mounted a drum 53 in which a vertically extending shaft 54 is rotatably sup- /ported by the ball bearings 55 and 56, these '.bearings, and hence the shaft, being eccent'rically positioned with respect to the drum 53.' They drum 53 is provided with a cam groove 58 (see Figures 4 and 7) extending peripherally thereof and within'this cam groove 58 is received a pin 59 which is mounted in the wall of the housing 52 and hence is stationary with respect to the drum 53. A handle .57 (see Figure 4)I is attached to the lower por-tion of the drum53 and permits the latter to be swuno about its axis at will. Suitable stops .130 (Figure 4) and 131 (Figure 1,) limit the movements of the handle 57 and hence ofthe drum 5 3 about the axis of the latter.

The upper end of the shaft 54 (see Figures 4 and 7) has rigidly secured thereto a spiral gear 63 and a worm 64.,y Thelower end of the shaft 54, projecting through the lower portion of the drum 53 through a stuiiing box 132 which acts to prevent lubricant from leaking out of the chamber 133 within the drum 53, is connected by'a universal coupling 66 (see also Figure 1) -toa telescoping shaft 67,

the lower end of which is in turn connected through a universal coupling 68 to the upper end of the shaft 11 which is rotatably supported, in a suitable housing upon the base of the main frame 1 as isclearl'y shown in Figure 1. This latter housing has extended into it a shaft 10, extending in a general hori- .zontal direction (see Figure 1) and drivenin any suitable manner (not illustrated) from the driving shaft 2. The shaft drives the shaft 11 by-means of the bevel gears 12.v

The universal couplings 66' and 68 will be seen to permit the swinging of the ram 39, frame 46 and hence the axis of the lower .wheel 50 about the axis of the ram 39, but without disturbing the driving connection, while the telescoping shaft 67 permits the maintenance of the driving connection even though the ram 39 with its associated parts is raised and lowered by means of the hand wheel 45. c

The worm 64 (Figures 4 and 7) on the 'shaft 54 may be placed in driving mesh with the worm wheel 62 on the spindle 49 of the work-rotating wheel 50, or the spiral gear 63 s may be placed in driving connection with thevv spiral gear 61 by manipulating the handle 57 and hence swinging the drum 53 about its 1 axis and within the housing 52. r" -The swingingthe of the drum 53 about its axis results in giving' the shaft 54 and hence the spiral 2 gear 63 and the worm 64 thereon a two-fold motion; the rotation of the drum 53, due to the eccentric mounting therein of the shaft 54, swings the shaft and the spiral. gear 63 and Worm 64 laterally, when the drum 53 is rotated in counter-clockwise direction, as viewed in Figure 8, from a position shown in dotted lines to the position of these parts shown in full lines in Figure 8,and this movement is accompanied by la downward movement in an'axial direction of the drum 53 and hence also of the shaft 54 with the spiral gear 63 and the worm 64 thereon. This downward movement is achieved by the action of the pin 59 upon the cam groove 58. These movements which, as will be clear, take place vconjointly, are effective to move the worm 64 out of mesh with the worm wheel 62 on the spindle 49 ofthe work-rotating wheel .and-

63 and 61, drives the spindle 49 many times as fast as it formerly did when it drove the spindle 49 through the worm 64 and the worm wheel 62. This change in the speed of driwe cf the Work-rotating wheel 50 is effected when it is desired to true or dress the wheel 50 since its normal operative speed, when being driven through the worin 64 and worm wheel 62, is inappropriate for the dressing or truing operation. The mechanism for dressing the wheel. will be hereinafter more clearly described. Movement of the handle 57 in reverse direction will, as will now be clear, change the driving connection so that the spindle 49 of the work-rotating wheel 50 will be driven at a suitably low speed through the worm 64 and worm wheel 62 and it is this that the universal couplings 66 and 68 and the telescoping shaft connection 67 (see Figure 1) act also to maintain the driving connection between the shaft 11 andthe shaft 54 even though the latter is swung about the axis of the drum 53 and is raised and lowered by the action of the camgroove 58 and pin 59 as the above-described speed changes are brought about.

The work which is to be reduced to cylindrical form and is indicate in Figures 1f and 3 at 101 is held in operative relation to 'the adjacent operative surfaces of the grinding wheel 18 and of the work-rotating wheel 50 by means of two Work-holding members 108 and'109, each of which is preferably in the form of la plate or bar-like member (see also Figure 5). Thework-holding members 108l and. 109 are held in spaced relationv and are'adjustable so as to' form with the two 4members 108 and 109 are mounted to be ading wheel 18. The member 108 is secured to `cured to the main frame 1.

a carriage 125 (see Figures 1 and 5) while the member 109 is mounted on and carried by a carriage 126. These carriages 125 and 126 are slidably mounted on a substantially horizontally extending frame portion preferably made up of two members 124 (see Figure 5) and one on each side of the grinding wheel 18. This frame portion made up of the members 124 is carried by a plate-like bracket 123 (see Figure 5) which extends outwardly from a slide 112 (see Figures 5, 6 and 1) which is slidably mounted in a bracket 111 suitably se- As will be clear lfrom Figure 6, the bracket 111 and the slide 112 are provided with suitable ways to permit the slide 112 to be moved in a vertical direction relative to the bracket 111.

The slide 112 is provided with a rack 115 (Figures 6 and 1) with which meshes, a gear 116 mounted on and driven by a shaft 117 journaled in a housing 118 secured to the bracket 111. The shaft 117 is provided with a worm wheel at its left-hand end, as viewed vin Figures 6 and 1, andwith this worm Wheel 120 a worm (not shown) mounted upon the shaft 121 (Figure 1) meshes. The shaft 121 may be rotated by the hand wheel 122 and by means of the latter the gear 116 is operated to raise or lower at will the rack 115 with its associated slide 112 from which, as above noted, the' carriages 125 and 126 are supported. A locking gib 113 (Figure 6) is controlled by a screw operated by the handle 114 to securely lock the slide 112 relative to the "bracket and thus to hold the carriage 112 and hence the work-holding members 108 and 109 into what vertical position these parts have been adjusted.

Thus, the carriages 125 and 126 .with their respective work-holding members 108 and 109 may be raised or lowered and hence adjusted toward or away from either of the two .l wheels.

The carriages 125 and 126, and hence the work-holding members 108 and 109, are adjustable toward or awa-y from each other by means of thel hand-operated screws 127, the carriages being, as above noted, slidable relative to the bar-like members 124 (Figure 5) by which they are supported. Thus, the grinding throat may be adj usted to accommodate therein different sizes or diameters of work which it is intended to operate upon.

The grinding wheel 18 and the work-rotating vwheel 15 are driven in respective directions indicated by the arrows in Figure 1, and it will be seen that'the adjacent operative surfaces of the two wheels travel in opposite directions; moreover, as will be clear from the foregoing, the worksrotating and feeding wheel 50 is driven at a. very lowrate of speed when the worm 64 and the worm wheel 62 (Figures 7 and 8) form the driving connection between the shaft 54 and the'spindle 49 of the wheel 50. Moreover, the axis of the work-feeding and rotating wheel 50 may, by reason of the construction whereby the frame 46 (Figure4) and the ram 39 may be swung about the axis of the latter, be made to be at an appropriate angle with respect to the axis of the workpieces held in operative relation to the two wheels by the work-holding members 108 and 109; the work-holding members 108 and 109 extend preferably parallel to the axis of the grinding wheel 18 so that the angularity between the axis of the slow wheel 50 and the axis of the work piece 101 will be substantially the same as the angularity between the axis of the slow wheel 50. and the axis of the grinding wheel 18. The angle between these axes may be varied considerably, but I have found that an angle of 70.

gives good results. Due to the angularity between the axis of the slow wheel 50 and the axis of the work 101, there will exist an inclination between the path of travel of the operative surface o f the slow wheel 50 and the path of travel of the work, as determined by the work-holding members 108 and 109, with the result that, as the two wheels are driven indirections above described, the work will be fed along in an axial direction and along the work-holding member 108 (which takes up the thrust of the grinding wheel 18 on -the.

work piece 101) by the action of the feed wheel-50.

As will be clear from Figure 2 and as already hereinbefore described, the lower wheel 50 has an operative face of greater width than e,

that of the grinding wheel 18 and, moreover, the two wheels are so related to each other that the lower or slowwheel 50 extends beyond the face ofthe grinding wheel and to either side of the latter. Thus, the work, held between the members 108 and 109 and resting upon the lower wheel 50, is made to be engaged and supported by the lower wheel 50, both before and after the work is engaged by the upper or grinding wheel. This relation and action result in a number of practical advantages. In the iirst place, the engagement of the work piece first by the lower wheel 50 causes the work to be set in rotation so that, as the lower or feed wheel 50, due to the relative inclination or angulari'ty above pointed out, causes the work to move along the guides or work-holding members 108 and 109, the work is brought into contact with the grinding wheel 18 in an already rotating condition. Similarly, as the work passes through and out of the range of the operating face of the grinding wheel 18, it continues to be turned or rot-ated by the wheel 50. Thismarring of the surface of the work piece by the grinding wheel is prevented. The attainment of these actions, moreover, is made 103 and 105, one on each side of the work-rotating wheel 50 and substantially alined with the upper surface thereof (see Figure 4). Upon the table 103 are mounted two guides 104 by meansof suitable cap screws passing into the table 103 ,and through transverse slots in the guide members 104, so as to permit the latter to be adjusted toward or away from each other. Upon the table 105 there arel provided l, two similarly adjustably mounted guides 106. The adjustment of the guides 104 and Ai106 will be understood to be for the purpose of accommodating the guides to the different sizes or diameters of work intended to be operated upon. t The work pieces may be supplied to the guides 104 by means of a downwardly inclined chute or trou h 102 whencethey are passed along the ta le 103, guided by the guides 104,k and thence passed from the table 103 onto the work rotating and feeding wheel 50 and in between the work-holding members 108 and 109. The extended portion of the wheel 50 effects av rotation of the work before the latter is engaged bythe grinding wheel 18, while the angularity or relative inclination above pointed out effects a move- V ment of the workpieces in an axial direction and'past the operative face of the grinding wheel 18. As the work pieces emerge from the range of action of the grinding wheel 18 they are continued to be rotated and fed along by the other extended portion of the wheel 50, -and from the latter they are passed onto the table 105 and in between the guides 106, for discharge out of the appa-v ratus. 4

In Figure 2 the line A-A indicates the direction in which the axis of the grinding wheel 18.extends, while the line B-B indicates the direction in which the axis of the feed wheel 50 extends, and the'angularity between these two lines indicates a possible arrangement of the parts for. effecting the feeding movement by the wheel 50 of the work pieces, it being further pointed out that, as will be clear from Figure 2, the line or path of travel of the work pieces, as determined by the entry guides 104, the work-holding members 108 and 109, and the exit guides, 106, is substantially parallel to the line A-A and makes a substantially'similar angle with y the line B-B, as does the line A-A.

In order to effect the truing or dressing of the work-rotating and feeding wheel .50 so that the work will move along the upper sur face thereof substantiall parallel to the axis ofthe grinding wheel, I ave rovided a truing mechanism, the features o which are best illustrated f in Figures 2 and 3. Referring particularly to Figure 3, it willbe noted that I have rovided a tiltable frame 72 carried by the rame 46 and pivoted to the latter by means of a pin 73 which provides a pivoting axis which is at right angles to a Vertical plane passing through the spindle 48 of the wheel 50i' The frame 72 is tiltable about the axis of the pin 73 and is, furthermore, se-

cured to a side face of the frame 46 by means of the bolts 74 (Figure 2), the parts being so constructed and arranged as to permit tilting of the frame 72 to the desired degree. The tiltable frame 72 is provided with a guiding way 75 for guiding a slide or carriage generally indicated at 76 and adapted to be moved along the guiding way 75. Preferably, a screw 7 7 is secured in the ends of the carriage 76 (see Figure 2) and a nut 78 is mounted upon the screw 77 and otherwise suitably supported in the frame 72 so that the spiral .teeth formed in the periphery of the nut 78 can mesh with a spiral gear 79 on the inner end of a shaft 80 which is rotatably mounted in the tiltable frame 72 and adapted by the hand wheel 82' to be manually rotated. As the shaft 80 is thus rotated, the nut 78 is rotated, and by reasonN of its action upon 'the screw 77 moves the carriage 76 back or forth along the guide 75. n

The carriage 76 carries or has formed therein a sleeve-like member 83 extending transversely ofthe carriage 76; within this sleeve 83 is a spindle 84 at the outer end of which is mounted a diamond 90. The member 84 is mounted to slide withinthe sleeve 83, while the latter-is split, the split portions of which may be clamped about the spindle 84 roo by means of the srew 85,130 securely grip the member 84 in its adjusted osition. Movement of the member 84 in a irection -along the sleeve 83,-is controlled by a" screw 87 which is in engagement with the nut 88 formingpart of the member 84. The spindle portion of the screw 87 passes through an .end orfcover plate 86 ofthe sleeve A83 and f 0bl 89, therefore, the i izo the spindle 49. Moreover, it will also be seen f from Figure 3 that the parts are so related that the diamond 90, when moved into a position to contact with the feed wheel 50, contacts with the latter at a point displaced .by substantially 90c from theI point or line at which the work piece 101 contacts with the wheel 50.

to the predetermined extent.

If the grinding wheel 18 is trued to a true cylinder, as will be more clearly described hereinafter, then, if the work 101 is to contact with a line or element of the cylindrical v peripheral surface of the grinding wheel 18, the work should be' held in operative relation to the grinding wheel 18 with its axis parallel to that of the grinding wheel itself. Also, the feed wheel 50 must be dressed so that it Will present a straight line of contact to thc work 101 as the latter is moved in an axial direction along and by the peripheral facel of the wheel 50, but by reason of the angularity and relative inclination lbetween thev axis of the wheel) to provide the abovementioned straight line of Contact to the work under the conditions above set fort-h. This is accomplished by tilting the frame 72 (Figure 3) and hence the guide 7 5 about the axis of the pin 73 through the same angle that exists between the path of travel of the work 101 and the axis of the feed wheel 50. This angularity, as already above described, will be seen to be that existing between the lines A.-A and B-B of Figur-e 2. And by way of further explanation of this action, it might be noted that where the axis of the Wheel 50 is in a horizontal plane and the an-gularity between the wheel 50 and the path of travel of the work (as viewed in this horizontal plane) is, for example, 7 o, the frame 72 is tilted about the axis of the\pin 73 to such an extent that the guideway 75, which determines the path of travel of the diamond 90 in a direction generally crosswise of the peripheralface of the wheel 50, makes an angle of 7 with the horizontal. The resultant move- .ment of the diamond across the face of the `wheel 50 at an angle to the axis of the latter,

as above typified, gives the wheel 50a curved surface but one which will present a straight line of contact to the work When the axis of the latter is inclined tol the axis of the wheel The depth of cut of the diamond 9 0 may be controlled by the knob 59 and screw 87 operated thereby. Moreover, also, as will be clear from 'Figure 2, the guideway 75 will be seen to be mounted substantially parallel to the axis (as indicated by the line B-B) of the wheel 50, as viewed .in plan. It Will also be noted that the frame 72 carrying the truing mechanism is mounted upon and carried by the frame 46 in which the work-rotating and feed wheel 50 is mounted and that the truing mechanism is thus made to partake of whatever movements of adjustment are given the wheel 50. Thus, the truing mechanism is effectively maintained in operative relation with the wheel 50 and much time and effort is saved in performing the truing operation and many other practical advantages achieved.

During the dressing operation upon the work-rotating and feeding wheel 50, the speed of the latter 1s changed by altering the driving connection between the spindle 49 and the shaft 54 (see Figure 4) by the mechanism hereinbefore described and, moreover, the

driving connection established for the dressing operation is the one in which the spiral gear 63 on the shaft 54 is made to mesh with and drive the spiral gear 61 on the spindle 49 of the wheel 50. The result is that the shaft 54 turns the spindle 49 of the wheel 50 many times as fastI as it was driven during the normal operation of the machine. The grinding Wheel 18 is trued by means of a diamond (see Figure 1) which is carried in the end of a spindle 96 mounted in a sleeve 95, the sleeve being mounted upon a carriage 93 in turn slidable along the support 94, which is carried by the grinding wheel housing 36, in a direction parallel to the axis of the upper -or grindingw'heel 18. By means4 of a knob provided for supplying the abrading surface of the wheel. 18 with a suitable liquid or coolant, the latter being caught up by a suitable casing or shield 91 (see Figures 1, 2 and 3) open at the top and provided at its bottom portion with. a suitable discharge spout 129 (see Figures 2and 4).

` The bearings 47 and 48 (see Figure 4) and spindle 49 which carries the work-rotating and feeding Wheel 50, may be lubricated in any suitable manner anl inconnection with bearing 48 I have shown channels and a conduit 70 leading to suitable grease cups 69 to supply lubrication to the bearings. It will thus be seen that there has been provided in this invention a grinding apparatus wherein the various 'objects hereinaboveset forth, as well as many thoroughly practical advantages, are successfully achieved, and that the apparatus is readily and convenientlyJ adapted` to the varying conditions of practical use. It might further be noted that great accuracy is attainable,

and that the grinding of round bodies t0 above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying'drawing, is ,to be inter- Y wheel.

'preted as' illustrative and not in a limiting sense.

I claimtl 1. A centerless grinding machine comprising a rotatably mounted grinding Wheel, a rotatably mounted spindle carrying a Work regulating Wheel, a driven shaft extending at an angle to said spindle, speed change gear mechanism directly connecting said shaft with the regulating Wheel spindle and arranged to rotate the regulating Wheel at a slow rate or a normal truing rate, and means for manually controlling said mechanism to secure either of said rates of speed.

2. A grinding machine comprising an abrasive Wheel, a spindle adapted to rotate the same, a shaft, a plurality of driving connections between the shaft and spindle, and means for imparting to the shaft a helical like movement so as to engage the driving connections to drive the spindle at either speed.

A centerless grinding machine comprising a rotatably mounted grinding Wheel, an arbor, a Work regulating Wheel mounted thereon, a longitudinally movable and rotatably mounted sleeve, a shaft associated With the arbor and eccentrically mounted in the sleeve, drive gears on the shaft, a plurality of driven gears on the arbor, and means for actuating the sleeve to engage the drive gear With either of the driven gears to change the speed of the regulating wheel.

4. A centerless grinding machine ,com-

prising a base, a rotatably mounted grinding vvheel, a Work regulating Wheel mounted on an' arbor, a longitudinally movable sleeve mounted for rotation Within a cylindrical portion of the-base, a projection on the base adapted to engage a helical like groove in the sleeve, a shaft associated With the arbor and eccentrically mounted in the sleeve, a drive gear on the shaft, a plurality of driven gears on the arbor, and means for rotating the sleeve whereby the drive gear may be moved laterally and longitudinally to engage either of the driven gears to change the speed of the regulating Wheel.

5. A centerless grinding machine comprising a rotatably mounted grinding Wheel, a Work feed regulating Wheelmounted on an arbor, a shaft associatedWith the arbor, a worm and a spiral gear oiiv the shaft, a com- -panion Worm Wheel and spiral gear on the arbor, and'means to move the shaft longitudinally and laterally to engage alternately the spiral gears 'and then the Worm and Worm 6. A centerless grinding machine comprising a base, a rotatably mounted. grinding Wheel, a Work regulating Wheel mounted on an arbor, a longitudinally movable sleeve mounted for rotation Within a cylindrical portion of the base, a pin in the baseadapted to engagea spiral like groove in the sleeve,

a shaft associated With the arbor and eccentrically mounted 'in the sleeve, a Worm and a spiral gear on the shaft, a companion Worm lWheel and yspiral gear on the arbor, and means for rotating the drum whereby the shaft may be moved laterally and longitudinally to engage alternate-ly the spiral gears and then vlaterally relative to said spindle to engage alternately said spiral gears or said worm and Wor'm Wheel.

8. In apparatus of the character described, in combination, an abrasive Wheel, a spindle adapted to rotate said Wheel, a spiral gear and a Worm wheel on said spindle, a' companion spiral gear and a Worm adapted 'to mesh respectively With said spiral gear' and said Worm Wheel, means :for driving said spiral gear and Worm, and means for moving said spiral gear and Worm in a' direction length- Wise of said spindle and in a direction laterally of said spindle to effect engagement either'of said spiral gears or of said Worm and Worm Wheel, said means'including an eccentric.

9. In apparatus of the character described, in combination, an abrasive Wheel, a spindle adapted to rotate said Wheel, a spiral gear and a Worm Wheel on said spindle, a companion spiral gear and a Worm adapted to mesh respectively with said spiral gear and said Worm Wheel, means for driving said spiral gear and Worm, and means for moving said spiral gear and Worm in a direction lengthwise of said spindle and in a direction latterly of said spindle to effect engagement either of said spiral gears or of said Worm and Worm Wheel, said means including a cam member. v

10. Inapparatus of the character described, in combination, an abrasive Wheel, a spindle adapted to rotate said Wheel, a spiral gear and a Worm Wheel on said spindle, a companion spiral gear anda Worm adapted to mesh respectively with said spiral gear and said Worm Wheel, means for driving said spiral gear and Worm, means for moving said spiral gear and Worm in a direction length- Wise of said spindle and in a direction laterally of said spindle to effect engagement either of said spiral gears or of said worm and Worm Wheel, ysaid means including an eccentric for achieving movement of said spiral gear and Worm in one of said directions, and means responsive to the actuation of said eccentric for moving said spiral gear and worm in said other direction.

11. In apparatus of the character described, in combination, an abrasive wheel, a

spindle adapted to rotate said wheel, a spiral gear and a worm wheel on said spindle, a companion spiral gear and a worm adapted to mesh respectively with said spiral gear and said worm wheel, means for driving said spiral gear and worin, means for moving said spiral gear and w'orm in a direction lengthwise of said spindle and in a direction laterally of said spindle to effect engagement eitherof said spiral gears or of said worm and worin wheel, said means including an eccentric for achieving movement of said spiral gear and worm in one of said direc-t tions, and cam means effective upon the actuation of said eccentric for causing movement of said spiral gear and worm in said other direction.

12. In apparatus of the character described, in combination, an abrasive wheel,

a spindle adapted to rotate said wheel, a

spiral gear and a worm wheel on said spindle, a companion spiral gear and a worm adapted to mesh respectively with said spiral gear and said` worm wheel, means for driving said spiral gear and worm, means for moving said spiral gear and worm ina direction lengthwise of said spindle and in a direction later- 'ally of said spindle to effect engagement either of said spiral gears or of said worm and worm wheel, said means including a rotatable member in which said spiral gear and worm are eccentrically mounted and adapted upon rotatioiithereof to vcause movement 'of said spiral gear and worm in one of said directions, means rotatably supporting said member and adapted to permit movement thereof lengthwise of its axis, and means for moving said rotatable member lengthwise of its axis to effect movement of said spiral gear and worm in said other direction.

13. In apparatus of the character described, in combination, an abrasive wheel,

a spindle adapted to rotate said' wheel, a

spiral gear and aworm wheel on said spindle va companion spiral gear and a worm adaptedl to mesh respectively with said spiral gear and said worm wheel, means for driving saidl spiral gear and worm, means for moving said` spiral gear and worm in a direction length-` wise of said spindle and in a direction laterally of said spindle to effect engagement either of said spiral gears or of said worm and worm wheel, said means including a rotatable meinber in which said spiral gear and worm are eccentrically mounted and adapted upon rotation thereof to cause movement of said spiral gear and worm in one of said directions, means rotatably supporting said member and adapted to permit movement thereof lengthwise of -its axis, and means operative upon rotation of said rotatable member to to mesh respectively with said spiral gear and said worm wheel, means for driving said spiral ge'ar and worm, means for moving said spiral gear and worm 1n a direction .lengthwise of said spindle and ina direction laterally of said spindle to effect engagement either of said spiral gears or of said worm and worm wheel, said means including a rotatable member in which said spiral gear and worm are eccentrically mounted and adapted upon rotation thereof to cause movement of said spiral gear and worm in one of said directions, means rotatably supporting said member and adapted to permit movement thereof lengthwise of its axis, and cam means responsive to rotational movement of said rotatable means for effecting movementof the latter and hence of said spiral gearand worm in said other direction.

15. In apparatus of the character described, an abrasive wheel, a spindle adapted to drive said wheel, a plurality of gearson said spindle, a shaft carrying a ,plurality of gears each adapted to mesh with one of` said for giving said sha-ft a substantially helical path of movement to cause a gear on said shaft to mesh with a gear on said spindle.

16. In grinding apparatus, in combination, a -inain frame having rotatably supported at an upper portion thereof a grinding wheel and having a woilrrotating wheel rotatably supported substantially .underneath said rinding wheel, means for driving said grinding wheel at a grinding speed and for drivin said second-mentioned wheel at a speed an in a direction to control the rotation of -work of round section interposed between said. wheels, means for holding work in operative relation to saidtwo wheels, and means including a work-supporting member substantially alined with the upper surface of'said work-rotating wheel and adapted to support Vand guide a work piece relative to the upper :work supporting surface of said work-rotating wheel.

17. In grinding apparatus, in combination,

a main frame having rotatably supported at I an upper portion thereof a grinding wheel and having a work-rotating wheel rotatably `supported substantially underneath said grinding wheel, means for driving said grinding wheel at a grinding speed and for driving said second-mentioned wheel at a speed andA in a direction to control the rotation of work of roundf Vsection interposed between said wheels, means for holding work in operative relation to said two wheels, and two members one on each side of said work-rotating wheel and each substantially alined with the u per work-supporting surface of said wor rotating wheel, said means being adapted to support and aline a work piece with the latter as said work piece is moved into and out of operative relation to said two wheels.

18. In grinding apparatus, in combination, a main frame having rotatably supported at an upper portion thereofl a grinding wheel and-having a work-rotating wheel rotatably supported substantially underneath said grinding wheel, means for driving said grinding wheel at a grinding speed and for driving said second-mentioned wheel at a speed and in a direction to control the rotation of work of round section interposed between said Wheels, said work-rotating wheel having an operative surface of greater width and extended beyond the operative face of said grinding wheel, wherebysaid extended portion of said work-rotating wheel may support and effect rotation of work of round section when the latter is not in Contact with said grinding wheel, means for holding work of round section in operative relation-to said two wheels, and work-supporting and guiding means adjacent said extended portion of said work-rotating wheel and adapted to aline a work piece relative to the upper supporting surface of said work-rotating wheel.

19. In grinding apparatus, in combination,

. a main frame having rotatably supported at an upper portion thereof a grinding wheel i and having a work-rotating wheel rotatably supported substantially underneath said grinding wheel, means for driving said grinding wheel at a grinding speed and for drivin said second-mentioned wheel at a speed an in a direction to control the rotation of work of round section interposed between said wheel, said work-rotating wheel having an operative surface of greater width than and extended beyond each side of the operative surface of said grinding wheel, whereby said work-rotating wheel mayeffect rotation of work of round section prior to and after the work is operated upon by said grinding wheel, means for holding work of round section in operative relation to said two wheels, and means alined with the upper supporting surface of said work-rotating wheel and forming substantially an extension thereof for guiding a work piece onto the extended portion of said work-rotating wheel on one side of said grinding wheel and for guiding a work piece off of the extended portion of said work-rotating wheel on the other side of said grinding wheel.

20. In grinding apparatus, in combination, a main frame having rotatably supported at an upper portion thereof a grinding wheel and having a work-rotating wheel rotatably supported substantially underneath A said v grinding wheel, means for. driving said grinding wheel at a grinding speed and for driving' said second-mentioned wheel at a speed and in a direction to control the rota- 'tween said wheel, said work-rotating wheel having an operative surface of greater width t1on of work of round section interposed bewhereby said work-rotating wheel may effect rotation of work of round section prior to and after the work is operated upon by said grinding wheelmeans for holding work of round section in operative relation to said two wheels, the path of travel of the work along said work-holdin g means being inclined with respect to the path of travel of the operative surface of said work-rotating wheel, whereby the latter acts to feedv the work in an axial direction, and means alined with the1` upper supporting surface of'said work-rotating wheel and forming `substantially an extension thereof for guiding a work piece onto the extended portion of said workrotating wheel on one side of said grinding wheel and for guiding a work piece off of the extended portion of said work-rotating wheel on the other side of said grinding wheel as said work-rotating wheel feeds the work axially away from said grinding wheel. 'y

2l. In grinding apparatus, in combina-tion; a grinding wheel and a shaft therefor adapted to be rotated at a grinding speed, a workrotating wheel adapted to be rotated at a relatively low speed and in a direction so that said two wheels present adjacent operative -surfaces traveling in opposite directions,

means for holding work of round section in operative relation to said adjacent operative surfaces of said two wheels, said grinding wheel performing a grinding operation upon the work as the latter is rotated by saidworkrotating wheel, a belt and pulley for driving said grinding wheel, and means for preventing the pull of said driving belt from affecting" the lrelation of said grinding wheel to said work-holding means and said work-rotating wheel comprising means rotatably supporting said pulley independently of said grinding Wheel shaft, and a driving connection between csaid pulley and said shaft adapted to transmit wheel performing a grinding operation upon the work as the latter isrotated by said workerotating wheel, a belt and pulley for l driving said grinding wheel, means for preventing the pull of said driving `belt from affecting the relation of said grinding wheel to said work-holding means and said workrotating whe'el comprising means rotatably supporting said pulley independently of said v grinding wheel shaft but for rotation about an axis substantially coincident with the aXis of'said grinding wheel, and means forming Va driving connection between said pulley and opposite directions, means for holding work of round section in operative relation tosaid wheels, a spindle for rotating said workrotating wheel, a driving shaft, and speed change mechanism interposed between said spindle and said driving shaft, said mechanism including movable means driven by said shaft and adapted upon movement to change the speed of drive of said spindle and driving connections between said movable means and said driving shaft operative throughout the range of movement of said movable means.

24. In grinding apparatus, in combination, a grinding wheel adaptedA to be rotated at a relatively high speed, a work-rotating wheel adapted to be rotated at a relatively low speed and in a direction so that the adjacent oper# ative surfaces of said two wheels travel in opposite directions, means for holding work of round section in operative relation to said wheels, a spindle for driving said workrotating wheel and'having thereon a gear and a worm wheel, a ldriving shaft, a gear and worm movably mounted and adapted upon movement to have said second-mentioned gear mesh with said first-mentioned gear or to have said worm mesh with said worm wheel, and means formin a driving connection between said-driving s aft and said gear and worm and operative throughout the range of movement of the latter. l

25. In grinding apparatus, in combination, a inding wheel yadapted, to be rotated at a re atively high speed, a work-rotating wheel adapted to be rotated at a relatively, low speed and 'in a direction so that the adjacent operative surfaces of said two wheels travel in opposite directions, means for holding work of round section in operative relation to said wheels, means mounting said work-rotating wheel to permit the relation of its axis and hence to permit the inclination 4of the path of travel of its operative surface to be changed 'relative to the path of travel of Work along said work-holding means, speed change mechanismv movable throughout the range of change of position of the axis of said workrotating wheel and having a driving connection therewith, a driving shaft and l{iexible a grinding wheel adapted to be rotated at a relatively high speed, a work-rotating wheel adapted to be rotated at a relatively low speed and in a direction so that the adjacent operative surfaces of .said two wheels travel in opposite directions', means for holding work of round section in operative relation to said wheels, means rotatably mounting saidtwo wheels so that said work-rotating wheel is substantially underneath said grinding Wheel, said mounting means being adapted to permit said work-rotating wheel to be raised or lowered and to permit said work-rotating wheel to be tilted about a substantially'vertical axis, a driving shaft, speed change mechanism havingy driving connection with said worlcrotating wheel and adapted to be moved therewith and driving connections between said driving shaft and said speed change mechanism and operative throughout the range of movement of the latter. 

